csms (Computer System Management Planning and Maintenance)

COMPUTER SYSTEM MANAGEMENT PLANNING BY JAJATI MALLICK DEPART MENT OF COMPUTER SCIENCE & ENGINEERING ASSOCIATE PROFESSOR PIET & PSET, ROURKELA And Asish Kumar Dash DEPART MENT OF COMPUTER SCIENCE & ENGINEERING Senior Lecturer PIET & PSET, ROURKELA

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COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE

I express my profound gratitude and sincere thanks to Prof. S. BAHERA and Prof. A.K. Dash for their valuable suggestions, guidance, constant encouragement for writing this book. It has been a great learning process for me. I thankful to Purushottam School of Engineering & Technology for all the necessary help I get during this book writing. Last but not the least, I wish to gratefully acknowledge the moral support I receive from my students. This book is particularly meant and design for diploma sixth semester Computer science and Engineeri ng students in t he Odisha state.

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COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE CONTENTS

Preface 1.0

COMPUTER SYSTEM MANAGEMENT PLANNING ………………..

01

1.1

Need of Management in Computer Centers………………………………... Centers………………………………...

05

1.2

Types of Job Carried Out in Computers in an Organization……………….. Organization………………..

05

1.3

Duties and Responsibilities of personnel involved………………………… involved…………………………

06

1.4

Position of Different Levels………………………………………………… Levels…………………………………………………

07

1.5

Need of training staff ……………………………………………………….. ………………………………………………………..

08

1.6

Computer manufacture and installations in India…………………………... India…………………………...

09

1.7

Major vendors in computer hardware and software………………………... software………………………...

09

2.0

Selection of Computer System………………………………... System………………………………...

10

2.1

Selection and evaluation of appropriate configuration for different levels of Industries…………………………………………………………………… Industries……………………………………………………………………

10

2.2

Different Types of Industries and Their Computer requirements…………... requirements…………...

10

2.3

Selection and evaluation of appropriate configuration for different levels of Industries…………………………………………………………………… Industries……………………………………………………………………

11

3.0

SITE PREPARATION & INSTALLATION …………………………….

12

3.1

Plan for Computer Room layout based on Size…………………………….. Size……………………………..

12

3.2

Layout Factors and their effect……………………………………………... effect……………………………………………...

13

Computer Centre Designs: Physical Computer Centre Setup……………… Setup………………

14

Power Conditioning Equipment……………………………………………. Equipment…………………………………………….

15

3.3.1

CVT (Constant Voltage Transformer)……………………………………… Transformer)………………………………………

15

3.3.2

Uninterruptible power supply (UPS)……………………………………… (UPS)………………………………………

17

3.3.3

Isolation Circuits…………………………………………………………… Circuits……………………………………………………………

20

3.4

Interpretation of the Installation and Wiring Diagram……………………... Diagram……………………...

21

3.5

Steps for actual installation as per the manufacturer’s Specified procedure.. procedure..

23

4.0

COMPONENTS INSIDE THE COMPUTERS (PC) & THEIR INTERCONNECTION ……………………………………………………

26

4.1

Introduction…………………………………………………………………. Introduction………………………………………………………………….

26

4.2

Hardware-BIOS interaction………………………………………………… interaction…………………………………………………

27

3.2.1 3.3





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE 4.4.3

HDD (Hard disk drive) System drive) System Interfaces…………………………………. Interfaces………………………………….

34

4.4.4

Partitioning and formatting HDD………………………………………….. HDD…………………………………………..

40

4.4.5

Different Standards of Expansion Units ISA, EISA, VESA, PCI……….. PCI………..

48

4.5

The Post Sequence (Power-On Self-Test)………………………………….. Self-Test)…………………………………..

50

4.6

Keyboard Interface………………………………………………………… Interface…………………………………………………………

50

4.7

Steps for assembling of a computer ………………………………………… …………………………………………

51

4.8

Software settings of computer after installation (CMOS-setup)…………… (CMOS-setup)……………

52

5.0

Basic Maintenance of Computer and Trouble Shooting Procedures …………………………………………………………………

55

5.1

Basic maintenance concepts………………………………………………... concepts………………………………………………...

55

5.1.1

Preventive Maintenance…………………………………………………….. Maintenance……………………………………………………..

55

5.1.2

Corrective Maintenance…………………………………………………….. Maintenance……………………………………………………..

55

5.1.3

On-line Maintenance………………………………………………………... Maintenance………………………………………………………...

55

5.2

Type & nature of fault……………………………………………………… fault………………………………………………………

56

5.3

Diagnostic program and tools……………………………………………… tools………………………………………………

60

5.4

Give Firmware (POST) concepts…………………………………………… concepts……………………………………………

61

5.5

Fault elimination process…………………………………………………… process……………………………………………………

63

5.6

Systematic way of trouble shooting versus adhoc trouble shooting………... shooting………...

64

5.6.1

Symptom observation………………………………………………………. observation……………………………………………………….

64

5.6.2

symptom analysis…………………………………………………………… analysis……………………………………………………………

64

5.6.3

fault diagnosis………………………………………………………………. diagnosis……………………………………………………………….

65

5.6.4

Fault Rectification………………………………………………………….. Rectification…………………………………………………………..

65

6.0

BASIC Networking Devices and their interfacing ………….....................

66

6.1

Network Interfacing Card…………………………………………………... Card…………………………………………………...

66

6.2

Networking Interconnection Devices………………………………………. Devices……………………………………….

67

6.2.1

Hub………………………………………………………………………….. Hub…………………………………………………………………………..

67

6.2.2

Switch……………………………………………………………………….. Switch………………………………………………………………………..

68

6.2.3

Router ………………………………………………………………………. ……………………………………………………………………….

69

Types of Network Cable……………………………………………………. Cable…………………………………………………….

70

6.3





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE 1.1 Need of Management in Computer Centers

Normally, all computer centers are responsible for virtually similar tasks in all organizations, however, their focuses may not be the same. The computer center, one of the support departments in the college, offer a wide range of services to satisfy the general computational and information processing needs of the educational, research and administrative programs. Services Provided by Computer Center are

-

To provide computer-related services to personnel and customers To provide advice and consultancy for users To provide systems development services to users To provide data entry services for users To create and maintain IT standards and procedures To provide IT acquisition services to users To keep and protect IT and data assets To ensure that the organization has adequate/advanced IT progress, which is in line with the organization's vision To ensure that services provided are meeting with users' requirements

1.2 Types of Job Carried Out in Computers in an Organization

-

-

Providing computing capability, running programs and producing reports, printing documents, providing operations services, make sure that good performance is provided Providing Internet services: Set up Internet and Email accounts, managing mailbox, providing disks spaces for Web, providing security and virus warning, etc. Providing helps: Help users to solve computer usage problems, help users to develop simple applications, help users to keep their data, help on security Providing system development services: Develop system for users Providing data entry services: This is to capture data into the systems, during these days, such function seems to be obsolete now. Such services may include storing data in database, data protection by data backup and recovery. Scanning images into the systems is also considered as a part of this function. Providing consultancy services: Purchasing devices, installing hardware & software, help users to work more efficiently Providing training for users, recently, the use of e-Learning concept of training also implemented





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE 1.3 Duties and Responsibilities of personnel involved

Duties and responsibilities of person in computer centers are describe here

-

Data Processing Center: To process business data (Sales, Deposit/Withdrawal, Airline Ticketing, Student Registration, etc.) and produce summary report or other business documents

-

MIS Center: To provide information for managers and executives for making timely and quality decisions (usually continuing the work of data processing.

-

Data Center: To provide data for use by all departments (e.g. center to provide criminal records, population records (Khonthai.com), etc.)

-

Office Automation and Internet Center: To provide services to all departments with office automation and communication systems.

-

Computing Service Center (or Computer Center or IT Service Center): Basically, to provide services of all types related to business data processing, business applications, and maintenance services to all departments in the organization.

In the department various staff with different computer skills is being emplo yed. The data processing manager is the head of the department under which you have the computer analyst, programmer, operation manager, etc. There is probably no standard structure for data processing department. Precise responsibilities and reporting procedures vary. Figure 1 and 2 show some alternatives.

1
























2

1.4 Position of Different Levels

(i) Computer Center must announce the service se rvice level policies on:





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE 1.5 Need of training staff

- Due to the rapid growth of educational institutions there is an endemic shortage of good teachers. A big increase in the output of Masters and PhDs, particularly in Computer Science, is required. - A large number of faculty positions in in the Universities and engineering colleges and even in the IITs are vacant due to the dearth of persons interested in becoming academics. Encouragement in terms of good working conditions and emoluments emoluments are needed to attract competent faculty - R and D spending of the Indian software services services companies is relatively low. To go up the value chain IT companies have to innovate and invest in focused research. The reduction of cost of communication gave birth to the ―offshore‖ software development model. The recent emergence emergence of the ―Computing Cloud‖ should lead to the next step, namely, providing Software as a Service (SaaS). The rich experience gained in the international market of offering software services should be leveraged to create world class ―service products‖ from India on the ―Cloud‖ - Product companies need, besides an innovative product, huge investment, marketing, and the willingness to take risks. risks. A company which was initially successful in selling FORTRAN compilers in a protected market in India went bankrupt as soon as imports were allowed as the imported product which had a worldwide market sold compilers at less than half the price of the local product. One of the few notable successes as a 61 product company in India is TALLY which produced accounting software in 1980. It succeeded as the software was designed keeping in view the accounting practices in India. It was affordable to a large number of small and medium enterprises. This provided the volume essential to amortize the development cost of the product. TALLY TA LLY was able to continually continuall y improve its product by getting feedback feedba ck from its local users. No foreign competitor understood the nuances of the local accounting practices or could match the price. So training of staff must require for running the TALLY software. The committee should be given specifies terms of reference. There are obviously two choices open to management. They can recruit experience personnel and thus reap the benefit of that experience or they can re-train existing staff in computer techniques. In doing this, a number of





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE (b) Re – Training Training of Present Staff Advantages: (i) Retain existing loyalties. (ii) No need to spend time in teaching company operation (iii) Personality and ability already known. (iv) Acceptance to existing staff (assuming right people selected). Disadvantages: (i) Computer training necessary. (ii) Over familiarities with the way thing are done and reluctant to change the present methods. 1.6 Computer manufacture manufacture and installations in India

There was no government policy on computers. As part of the five year plans higher technical education was promoted and five Indian Institutes of Technology and 13 Regional Engineering Colleges, one in each state, were established. The Directorate General of Technical Development and the Department of Defence Supplies controlled the area of computers. Foreign companies were permitted to manufacture and sell computers provided foreign exchange was not required. Computers were not considered a priority area that deserved foreign exchange outflow. IBM of the USA and the British Tabulating Machines (which was later named International Computers Ltd., ICL) were already selling mechanical unit record equipment, namely, key punches, verifiers, sorters, tabulators and accounting machines to a large number of companies, the Indian Railways, and statistics departments. Before a computer is received at the user’s premises the data processing manager must give many man- hours of thought to the preliminaries and must draw up detailed plans for the three major phases, - Pre installation - Installation and - Productive running Beside, there are also (i) Detailed planning (sitting, systems and programming, staffing etc) and (ii) Policy planning (The definition of objectives, budgeting and resources allocation)





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE 2.0 Selection of Computer System 2.1 Factors affecting selection and evaluation of Computers Computer system users, administrators, and designers are all interested in performance evaluation since their goal is to obtain o btain or provide the highest performance at the lowest cost. This goal has resulted in continuing evolution of higher performance and lower cost systems leading to today’s proliferation of workstations and personal computers, many of which have better performance than earlier supercomputers. As the field of computer design matures, the computer industry is becoming more competitive, and it is more important than ever to ensure that the alternative selected provides the best cost performance trade-off. Performance evaluation is required at every stage in the life cycle of a computer system, including its design, manufacturing, sales/purchase, use, upgrade and so on. A performance evaluation is required when a computer system designer wants to compare a number of alternative designs and find the best design. It is required when a system administrator wants to compare a number of systems and wants to decide which system is best for a given set of applications. Even if there are no alternatives, performance evaluation of current system helps in determining how well it is performing and whether any improvements need to made. The first step in performance evaluation is to select the right measures of performance, the right measurement environments, and the right techniques. The goal is to emphasize simple techniques that help solve a majority of day-to-day problems. Examples of such problems are specifying performance requirements, evaluating design alternatives, comparing two or more systems, determining the optimal value of a parameter (system tuning), finding the performance bottleneck (bottleneck identification), characterizing the load on the system (workload characterization ), determining the number and sizes of components (planning), and predicting the performance at future loads (forecasting). Here a ―system‖ could be any collection of hardware, software, and firmware components. It could be a hardware component, for example, a central processing unit (CPU); a software system, such as a database system; or a network of several computers. 2.2 Different Types of Industries and Their Computer requirements





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE software, call centres etc. The call centres operate 24 x 7 for worldwide customers and require language proficiency mostly in English and some European languages. Business Process Outsourcing (BPO) is primarily performing the back‐office work of a number of organizations, the largest segment being banks and insurance companies. The back‐office work was typically accounts receivable, payroll processing, account reconciliation, inventory management, and similar jobs. American Express was the first organization to start BPO work in India in 1994 followed by GE Capital International Services in 1997 [101]. The success of these pioneers induced a large member of Indian companies to start BPO Centres for foreign clients in SEZs as the profit earned at these locations was tax exempt. The cost of starting a BPO was low as the cost of computer hardware as well as that of communication communication fell rapidly. The only requirement was trainable human resources with good knowledge of English (which was available in reasonable numbers) and identification of overseas clients. BPOs were established not only by Indian companies performing tasks for off‐shore off‐shore clients but also by many British and American companies who shifted their back‐office data processing to India as they could get better quality employees and infrastructure at a lower cost. The falling cost of communication immensely helped the expansion of BPOs. 2.3 Selection and evaluation of appropriate configuration for different levels of Industries

A generic evaluation and selection methodology has been formulated to meet the specific configuration for different levels of industries (i). Identification of possible vendors and manufacturers. (ii). Primary elimination of irrelevant candidates. (iii). Determination of mandatory requirements. (iv). Examination of vendors' compliance with mandator y requirements. (v). Setting quantitative and qualitative criteria and respective weighing scale. (vi). Writing the RFP to be addressed to selected vendors. (vii). Receiving, comparing and analyzing bids. (ix). Concluding final list of vendors. (x). Performance of hardware and software benchmarks. (xi). Drawing final conclusions and selection of best computer family.























COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE (i). Vendor qualifications. (ii). Differences in hardware implementation. (iii). Software architecture. (iv). Software availability (V) Price/performance (vi) Future growth potential (vii) Rick factors





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE 3. Site Preparation Preparation and installation 3.1 Plan for Computer Room layout based on Size The environmental conditions of a computer are a re important to trouble -free running. All necessar y conditions must be met before installation exercise. The layout of the computer room should be design with work flow in mind as we have in figure 4 below:

Figure 4: Computer Room Layout

The operator should be near to the input and output units which are most in use e.g. card or tape reader, printer, and tape or disc unit. The room must have air condition used for dust filtration, temperature control and humidity control.





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE stepped up because of the activities of looters. Security attention should be given to the computer hardwares because of their small sizes; if the p hysical security is slack valuable and costly component of the system might be lost. c) Dust: It is almost always advisable to provide dust cover on computer equipment when not in use, and in some areas special dust filters may be needed to prevent dust penetrating the casing. d) Heat: Because of the heat been produced by the computer, full air conditioned office is highly imperative. It is advisable to buy portable air con dition unit or install cooling fan in micro itself. e) Power Supply: Computers can not function without electricity. Electric generators must be provided at the centre incase of the public power supply failure. In addition, the generator should be supported with power stabilizer and uni nterruptible power supply (UPS). Power stabilizer protect the computer the harmful effects of fluctuations while UPS maintain the continuity of power supply in the gap between the switch over public supply to in- house generator or vise – vise – versa. versa. f) Humidity: An unusually assemble of humidity can also be a problem, leading to corrosion of electric contact; it may be advisable to use non- corrodible plugs and socket or to use a contact less keyboard for example. g) Accessories: It is essential to have a supply of computer co mputer accessories and part of a micro and all peripheral equipments. h) Workshop: Basic maintenance facilities will be needed. It is not necessary to be an electronic engineer to do routine maintenance such as disc head alignment, to change board in the computer, or to run the diagnostics programs which will at least help to locate a fault. i) Communication Facilities: These facilities must be provided to provide a link between the





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE               

Machine room Operator working area Storage for paper, tapes, disks and outputs Customer engineer working area Technician area System development areas: for system analysts and programmers Library: for storing books, journals and software Conference and meeting rooms Training rooms Director rooms Secretary rooms Operator and guest areas Toilet Rest rooms Areas for storing power units and air conditioners: such areas are needed to be designed so that there will be no harm in case of power supply shortage.  Separation into air-conditioned and non air-conditioned areas  Floor preparation for equipment installation in the air condition areas  Quiet zone in personnel areas (management offices, system support, operations scheduling, visiting programmers, library, conference room, coffee room).  Solid and soundproof walls (over 40 dB in passage ways to separate air conditioned from non air-conditioned and noisy from quiet areas)  Extensive use of moveable walls to allow for ongoing adjustments to technical and taskrelated developments  Important features of a power supply to consider when purchasing it are its form factor, wattage capacity, number and type of connectors it provides, fan size, support for dual video cards, and warranty. To decide on the wattage capacity of a power supply, add up the wattage





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE change of voltage across the primary there is a corresponding change in the secondary voltage depending upon the ratio of the turns on the two windings. However, in a CVT the primary and secondary windings are wound separately from each other, as illustrated in figure. To set up field in between the coils, a separate shunt path is provided between the two windings but an airgap is formed in the shunt path. A capacitor is connected across suitable tappings of the secondary winding. The constructional details of a CVT are shown in the figure.
























Safety Unless phasing circuits are fitted all circuits should use 'break before make contactors and





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE provides power conditioning, power regulation and, in case of power outages, provides the crucial backup power needed for an orderly shutdown of computer processes and files. UPS are also used for emergency power supplies for Hospitals, data centers, municipalities, industrial and commercial centers to supply power in case of o f power failure from main supply authority.






















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COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE Easy to use: single-chip, complete isolation solution

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COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE The following tools might not be essential, but they are very convenient: - Cans of compressed air (see Figure 1-39), small portable compressor, or antistatic vacuum cleaner to clean dust from inside a computer case Cleaning solutions and pads such as contact cleaner, monitor wipes, and cleaning solutions for CDs, DVDs, tapes, and drives























COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE to the pink port. The blue port is the line in, which can be used with other types of devices. Some speakers, headphones, and microphones have USB connectors instead of the usual audio plug. These can be connected to any USB port. In addition, many computers have speakers or microphones built into the monitor. 7. Locate the two power supply cables that came with your computer. Plug the first power























COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE 5. Computerized systems should be maintained in the validated state with risk-based controls appropriate to the different stages of the system life cycle. These stages include system planning, specification, programming and configuration, system testing, preparation and verification of standard operating procedures (SOPs) and training system operation and maintenance including handling of software and














































COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE 4. COMPONENTS INSIDE THE COMPUTERS (PC) & THEIR INTERCONNECTION 4.1 INTRODUCTION Computers store information digitally. All the information stored as numbers, in a binary system. A binary system system has only two numbers 0 and 1. (Decimal system system











































































































































































































































































































































































































































































































































































































COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE by firmware by firmware or software software routines immediately after a computer or other digital electronic device is powered on. The results of the POST may be displayed on a panel that is part of the device, output to an external device, or stored for future retrieval by a diagnostic tool. Since a self-test might detect that the system's usual human-readable display is non-functional, an indicator lamp or a speaker a speaker may be provided to show error codes as a sequence of flashes or beeps. In addition to running tests, the POST process may also set the initial state of the device from firmware. Most computer peripherals are themselves special-purpose computers. Devices such as printers, scanners, cameras and USB and USB flash drives have internally stored firmware; some devices may also permit field upgrading of their firmware. - Firmware is programming that's written to a hardware device's nonvolatile device's nonvolatile memory. - Firmware, which is added at the time of manufacturing, is used to run user programs on the device and can be thought of as the software that allows hardware to run. Hardware makers use embedded firmware to control the functions of various hardware devices and systems, much like a computer’s operating system (OS) OS) controls the function of software applications. - Firmware may be written into read-only memory (ROM), (ROM), erasable programmable readonly memory (EPROM) or (EPROM) or flash flash memory. Firmware memory. Firmware that is embedded in flash memory chips can be updated easier than firmware written to ROM or EPROM, which makes it more adaptable. - Firmware updates are often issued to fix bugs, fix bugs, roll roll out new features and improve security.





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE 5.5 Fault elimination process Fault finding is a technique. Some faults can be easily traced out if one proceeds systematically, starting from the symptoms. Some fault show complex symptoms with no clue at all. For such faults there are no defined starting points. In such case, service engineers should try out an appropriate elimination process. The steps of fault elimination procedure are common to any computer. Some of these can be omitted depending on the symptoms. (I) Dead System: A computer is said to be dead when an absolutely essential signal is absent. It is easy to confirm whether a system is dead or alive. The following are some of the symptoms of adead computer: - DC voltage is absent - clk signal signal is absent - ROM output is inactive - Microprocessor is faulty or dead - The ac fuse is blown (II) Spurious Problems: Sometimes the computer malfunctions randomly. Logical and systematic trouble shooting may not yield any clue. In such case the engineers should look for symptoms of spurious problem. Some of the hidden symptoms of spurious problems are – are – - DC voltage has excessive ripples - DC voltage is noisy - clk signal is not stable - loose contacts of cables and connectors - there is noise pick up on the next input or on other bus signals. (III) Security Failures: In any computer, sometimes there are abnormal symptoms, due to malfunctioning of special hardware meant for error detection. Three types of problems are caused by such security logic: - When there is no error, the error detection logic (ex. ECC ch..) raises a false alarm. - When there is an error, the security guard without catching it. The error propagates and creates confusion. - The error detection hardware malfunctions in generating appropriate coding. For example, the parity generator may generate a wrong parity bit. This goes unnoticed immediately when the parity checker detects an error, the OS wrongly considers it a genuine error. (IV) Heart Beats: We have seen some of the symtoms of a dead PC earlier. These are the general symptoms applicable to any computer. In addition, there are some check points which are the heart beats of PCs. By sensing these, the engineer can predict the problem type and determine how to proceed with diagnosis. Two





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE . Microprocessor is alive. Initial start-up is successful. Reset sequence had been completed. . Microprocessor firmware has successfully initialized the refresh counter. . The refresh logic is functioning properly. . the data bus, address bus and control bus are reasonable error free. - Timer 0- Ticks: Ticks: The PC maintains the time of day. This time is periodically updated by the cooperation between timer 0 and timer interrupt service routine. The timer 0 (PIT) raises Tick periodically and the system uses these interrupt signals to update the time.

5.6 Systematic way of trouble shooting versus adhoc trouble shooting - Symptom observation - symptom analysis - fault diagnosis - Fault Rectification

Adhoc techniques of troubleshooting don’t always help an engineer. Systematic trouble shooting is a logical approach. It is a scientific and analytical process. The systematic troubleshooting approach can be divided into the following steps: - Symptom observation - symptom analysis - fault diagnosis - Fault Rectification (I) Symptom observation The first step in troubleshooting a system or peripheral is observing all the symptoms caused by the fault in the system. For some problems, especially for problems due to multiple faults, it will be impossible to locate the exact fault or it will take a long time & thus the downtime will be increased. The time spent on symptoms observation in turn will yield proportional return during fault locating. Clean mind and concentration is essential while troubleshooting a problem. Certain complex problems can be understood only if the engineer has an overall idea of the system functioning of various software routines and sequences performed by POST, BIOS and OS. (II) Symptom analysis A careful analysis of the symptoms will give a clue to the fault location process. When there are multiple symptoms the engineers should try to correlate the various symptoms to identify the problem. If any relationship or clue is found, several steps can be skipped during fault location, thereby reducing the downtime considerably. In cases where there is no interrelation between the symptoms of a problem, the engineer should proceed with the fault location, without wasting time in attempting to establish the relationship. If multiple faults are present, then we may be minted by mixed symptoms. It is difficult to predict the presence of multiple faults. Two probable clues are Symptoms are not consistent but keep changing





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE (III) Fault diagnosis It is highly sophisticated scientific process. The most important point is the multidimensional view to be applied by the hardware engineer while troubleshooting. The main dimensions are - Architecture: Certain problems can be visualized properly only when you analyze the problem and the behavior of the computer as a system consisting both hardware and software. Software may be either a system software or an application software. It is not necessary that we should be a programmer. But we should know what the programs do, when they start and stop some activities and when they interact with hardware. - Organization: Different faults may create the same external symptom. The engineer must distinguish the different faults by a deep analysis of the internal machine status. Every computer has certain unique organizational aspects. Before trouble shooting a computer, the engineer should understand the specific detail of organization of the computer. The computer with same architecture need not have the same organization. The hardware organization refers to functional and physical distribution of various subsystems in the computer. It decided by the computer designers based on the status of computer technology during the design state. Hardware engineer should know the organizational aspects including detailed timing relationship and signal sequences. Even if the engineer fortes all the signals in a computer system, he won’t be able to locate the fault if he does not know how correlate the various signal conditions. Engineering Layout: Certain Layout: Certain problems are caused by b y mere physical layout faults: Faulty cable, loose connection, open wire, track short, etc. To catch these problems, one must thoroughly analyze the physical aspects. The layout documents to a computer are – are – Circuit diagram Board layout diagram Cable Signals Connecter signals list Jumper settings Environment: Certain Environment: Certain problems are caused due to environmental conditions and are listed below: - High Temperature - DUST - Magnetic - Fields Humidity (IV) Fault Rectification: Once a problem is diagnosed thoroughly and the fault is traced, the rectification involves skilled mechanical work rather than analytical work. This step involve performing one or more of the actions depending on the result of fault diagnosis: - Replacing a defective IC or other components - Replacing a defective PCB





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE 6.0 BASIC Networking Devices and their interfacing 6.1 Network Interfacing Card In the list of networking devices, NIC stands on first place. Without this device, networking cannot be done. This is also known as network adapter card, Ethernet Card and LAN card. NIC allows our PC to communicate with other PCs. Basically it converts data transmission technology. A PC uses parallel data transmission technology to transmit data between its internal parts while the media that connects this PC with other PCs uses serial data transmission technology. A NIC converts parallel data stream into serial data stream and vice versa serial data stream is get converted in parallel data stream. Usually all modern PCs have integrated NICs in motherboard. NICs are also available separately. Fordesktop or server system they are available in adapter format which can be plugged into the available slots of motherboard. For laptop or other small size devices they available in PCMCIA (Personal Computer Memory Card International Association) card format which can be inserted in PCMCIA slots. Types of NICs There are two types of NICs Media Specific :- Different types of NICs are required to connect with different types of media. For example we cannot connect wired media with wireless NIC card. Just like this, we cannot connect coaxial cable with Ethernet LAN card. We have to use the LAN card that is particularly built for the media type which we have. Network Design Specific :- A specific network design needs ne eds a specific LAN card. For example ex ample FDDI, Token Ring and Ethernet have their own distinctive type of NICs card. They cannot use other’s NIC other’s NIC card.

Collision Collision is the effect of two devices sending transmissions simultaneously in Ethernet. When they meet on the physical media, the signals from each device collide and damaged. Collision domain is the group of devices that share same collision effects over the Ethernet network. It is a mechanism of removing collision from network. When two or more nodes simultaneously sense the wire and found no signals, and each device places it’s signal on the wire. These signals would be collide in wire and a collision will occur. Before placing any signal in wire, NIC (Network Interface Card) examines wire for any existing signal. This method is known as CS (Carrier Sense). If two NICs sense wire on exactly same time and see no signal then both will place their signals in wire. This is known as MA (Multiple Access). If the NICs see a collision for their transmitted signals, signals, they have to resend
























The more devices you place on a segment, the more likely you are going to experience the collisions. More devices means more random time interval, creating even more collisions, gradually slowing down a device’s access wh en trying to transmit the data.

6.2 Networking Interconnection Devices . Hub .Switch . Router

6.2.1 Hub Hub is a device works on the physical layer of OSI Models which create single broadcast domain & single collision domain. It is a layer 1 device. Hub use the method of Broadcast data transmission. Characteristics of HUB:1) Hub creates single Broadcast Domain. 2) Hub creates single Collision Domain. HUB is used to connect multiple computers in a single workgroup LAN network. Typically HUBs are available with 4,8,12,24,48 ports. Based on port type, there are two types of HUB:-





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE on its port, it repeats the the signal and forwards that signal from from all ports except the port on which the signal arrived. arrived. There are two types of HUB Passive HUB :- It :- It forwards the data signal from all ports except the port on which signal arrived. It doesn’t interfere in data signal. Active HUB :- :- It also forwards the data signal from all ports except the port on which signal arrived. But before forwarding, it improves quality of data signal by amplifying it. Due to this added features active HUB is also known as repeaters. Usually HUB has one or more uplink ports p orts that is used to connect it with another a nother HUB. Right cable type is required to connect co nnect two HUBs. Logically HUB creates a star topology where it sits in the center of the topology and all connected systems stays at the points of the star. star.

Physically HUB creates a bus topology where all connected systems share the same bus connection. There are two similar devices to HUB, MAU and PatchPanel.

6.2.2 Switch Switch is a device works on the Data Link Layer of OSI Models which create single broadcast & multiple collision domains. It is a layer 2 device & works on MAC address. Switch use the method of Unicast data transmission. Switch maintain a table which called MAC Address Table. In this table switch store Mac Address & Port no. of all the hosts attached on this network. ne twork. That’s why Switch is more intelligent.Switch stores the MAC table in a IC (integrated chip) called ASIC (Application Specific Integrated Circuit). Characteristics of SWITCH:1) Switch create single Broadcast Domain. 2) Switch create multiple Broadcast Domain. Switch is also used to connect multiple computers together in a LAN segment. Switches available with 4,8,12,24,48,64 ports. Each switch port has a separate separate collision domain. Switch works at layer two in OSI Layer model. At layer two data signals are formatted in frames. When a switch receives frame, it checks FCS (Frame checksum sequence) field in it. Switch process the frame only if it is valid. All invalided frames are automatically dropped. All valid frames are processed and forwarded to their destination MAC address. Switch makes their switching





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE invalid frames are automatically dropped. Among these three methods, this method has highest latency. Latency is the time taken by device in passing frame from it. Cut and Through Cut and Through method has lowest latency. In this method Switch only read first six bytes from frame after the preamble. These six bytes are the destination address of frame. This is the fastest method of switching. This method also process invalid frames. Only advantage of this method is speed. Fragment Free This is a hybrid version of Store and F orwar d method method and Cut and Through method . It takes goodies from both methods and makes a perfect method for switching. It checks first 64 bytes of frame for error. It processes only those frames that have first 64bytes valid. Any frame less than 64 bytes is known as runt. Runt is an invalid frame type. This method filters runt while maintaining the speed.

6.2.3 Router Router is a device works on the Network Layer of OSI Models which creates no Broadcast Domain & Collaisen Domain. Router prevent Broadcast. It is a Layer 3 device works on IP Address. Router has mainly 2 types of interface.Ethernet or LAN interface & Serial or WAN interface. Router maintain a table called Routing Table. It holds the Information of IP Addresses, Interface & HOP of all the hosts connected to this network.HOP means jump. How many router I have to jump to go to the recipient that is HOP. Basically routers are used :- To connect different network segments. - To connect different network protocols such as IP and IPX. - To connect several smaller networks into a large n etwork (known as internetwork) - To break a large network in smaller networks (Known as subnet usually created to improve the performance or manageability) - To connect two different media types such as UTP and fiber optical. - To connect two different network architectures such as token ring and Ethernet. - To connect LAN network with Telco company’s office (Known as DTE device). - To access DSL services (known as DSL DS L Router).





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE 6.3 Types of Network Cable In networks using cable-based media, there are three basic choices:

.Twisted pair .Coaxial .Fiber-optic Twisted pair and coaxial cables both use copper wire to conduct the signals electronically; fiber-optic cable uses a glass or plastic conductor and transmits the signals as light. (A) Twisted Pair Cable - Two main types of twisted-pair cabling are in use today: Unshielded Twisted Pair (UTP) and Shielded Twisted Pair (STP) . UTP is significantly significantly more common than STP and is used for most networks. Shielded twisted pair is used in environments in which greater resistance to EMI and attenuation is required. The greater resistance comes at a price, however. The additional shielding, plus the need to ground that shield (which requires special connectors), can significantly add to the cost of a cable cable installation of STP. STP provides the extra shielding by using an insulating material that is wrapped around the wires within the cable. This extra protection increases the distances that data signals can travel over STP but also increases the cost of the cabling. - There are several categories of twisted-pair cabling. The early categories are most commonly associated with voice transmissions. The categories are specified by the Electronic Industries Association/Telecommunications Industry Association (EIA/TIA). EIA/TIA is an organization that focuses on developing standards for electronic components, electronic information, telecommunications, and Internet security. These standards are important to ensure uniformity of components and devices. EIA/TIA has specified a number of categories of twisted-pair cable: - Category 1: 1: Voice-grade UTP telephone cable. Due to its susceptibility to interference and attenuation and its low bandwidth capability, Category 1 UTP is impractical for network applications.. - Category 2: Data-grade 2: Data-grade cable that can transmit data up to 4Mbps. Category 2 cable is too slow for networks. It is unlikely that you will encounter Category 2 on any network today. - Category 3: 3: Data-grade cable that can transmit data up to 10Mbps with a possible bandwidth of 16MHz. For many years, Category 3 was the cable of choice for twisted-pair networks. As





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE - Category 6: High-performance 6: High-performance UTP cable that can transmit data up to 10Gbps. Category 6 has a minimum of 250MHz of bandwidth and specifies cable lengths up to 100 meters with 10/100/1000Mbps transfer, along with 10Gbps over shorter distances. Category 6 cable typically is made up of four twisted pairs of copper wire, but its capabilities far exceed those of other cable types. Category 6 twisted pair uses a longitudinal separator , which separates each of the four pairs of wires from each other. This extra construction significantly reduces the amount of crosstalk in the cable and makes the faster transfer rates possible. - Category 6a: 6a: Also called augmented 6. Offers improvements over Category 6 by offering a minimum of 500MHz of bandwidth. It specifies transmission distances up to 100 meters with 10Gbps networking speeds.

Coaxial Cable Coaxial cable, or coax as it is commonly called, has been around for a long time. Coax found success in both TV signal transmission and network implementations. Coaxial cable is (B)























COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE of all cable media. Anyone trying to access data signals on a fiber-optic cable must physically tap into the medium. Given the composition of the cable, this is a particularly difficult task. Two types of fiber-optic cable are available: - Multimode . Multimode fiber : Many beams of light travel through the cable, bouncing off the cable walls. This strategy actually weakens the signal, reducing the length and speed at which the data signal can travel. - Single-mode fiber: Uses fiber: Uses a single direct beam of light, thus allowing forgreater distances and increased transfer speeds.

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It is used for to connect a router through console port to a pc through serial port.

6.4 Types of Network Connector A variety of connectors are used with the associated network media. Media connectors attact tp the media and allow the physical connection into computing device. Many of the fiber and the copper networks are used for sending data from the one place of the world to the corner of it.






















(IV)

small plastic connectors used on telephone cables. They have capacity for six small pins. The RJ-45 connectors are used with twisted-pair cabling and have capacity for eight small pins. F-type connectors are screw-on connections used to attach coaxial cable to devices. This includes RG-59 and RG-6 cables. F-type connectors are commonly associated with connecting Internet modems to cable or satellite Internet service provider’s (ISPs’) equipment.





















COMPUTER SYSTEM MANAGEMENT PLANNING & MAINTENACE Appendix A


































































csms (Computer System Management Planning and Maintenance)

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